Ios <；数组的UITableView滚动索引；FBGraphUser>；物体

真的被这个难倒了需要一些帮助！我正在创建UITableViewController的子类以显示FB好友列表（FBFriendPickServiceController对我有几个限制）。我能够检索id数组并按字母顺序排序

然而，仍然无法从这里找到一种方法来创建一个单独的字典，将FB用户按字母顺序划分为多个部分进行索引

-(void)captureFacebookFriendUsers
{
    //Issue a Facebook Graph API request
    NSLog(@"%@", NSStringFromSelector(_cmd));
    [FBRequestConnection startForMyFriendsWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error){
        if (!error) {
            NSLog(@"No error requesting friends");
            friendsObjects = [result objectForKey:@"data"];  //Objects are id<FBGraphUser>
            friendsNames = [NSMutableArray arrayWithCapacity:friendsObjects.count];
            NSMutableArray *friendIds = [NSMutableArray arrayWithCapacity:friendsObjects.count];
            //Create a list of friends' Facebook IDs
            NSSortDescriptor *firstNameDescriptor = [[NSSortDescriptor alloc]initWithKey:@"first_name" ascending:YES];
            friendsObjects = [friendsObjects sortedArrayUsingDescriptors:@[firstNameDescriptor]];

        for (NSDictionary *friendObject in friendsObjects) {
            [friendIds addObject:[friendObject objectForKey:@"id"]];
            [friendsNames addObject:[friendObject objectForKey:@"first_name"]];
        }
}

-（无效）captureFacebookFriendUsers
{
//发出Facebook图形API请求
NSLog（@“%@”，NSStringFromSelector（_cmd））；
[FBRequestConnection startForMyFriendsWithCompletionHandler:^（FBRequestConnection*连接，id结果，NSError*错误）{
如果（！错误）{
NSLog（@“请求好友时无错误”）；
friendsObjects=[result objectForKey:@“data”]；//对象是id
friendsNames=[NSMutableArray阵列容量：friendsObjects.count]；
NSMutableArray*FriendId=[NSMutableArray阵列容量：friendsObjects.count]；
//创建好友的Facebook ID列表
NSSortDescriptor*firstNameDescriptor=[[NSSortDescriptor alloc]initWithKey:@“first_name”升序：是]；
friendsObjects=[friendsObjects SortedArray使用描述符：@[firstNameDescriptor]；
for（friendsObjects中的NSDictionary*FriendsObject）{
[friendIds-addObject:[friendObject-objectForKey:@“id”]；
[FriendsNamesAddObject:[friendObject objectForKey:@“名字”]；
}
}

---

感谢您花时间阅读此内容！

您需要为此使用UILocalizedIndexedCollation，并调用[self.collation sectionForObject:friend collationStringSelector:@selector（name）]以获取与设备区域设置的好友名称相对应的节的索引。 要做到这一点，您需要将好友数据存储在一个具有属性“name”的类中（可能有一种方法可以继续对我不知道的好友数据使用NSDictionary）

下面是一些代码：

// View Controller code

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self condigureSections];
}

- (void)configureSections
{
    // UILocalizedIndexedCollation
    self.collation = [UILocalizedIndexedCollation currentCollation];

    NSInteger index, sectionTitlesCount = [[self.collation sectionTitles] count];
    // new sections with data
    NSMutableArray *newSectionsArray = [[NSMutableArray alloc] initWithCapacity:sectionTitlesCount];

    // allocate data array for each of the sections
    for (index = 0; index < sectionTitlesCount; index++) {
        NSMutableArray *array = [[NSMutableArray alloc] init];
        [newSectionsArray addObject:array];
    }


    // Put friends into the appropriate sections
    for (Person *friend in self.friends) {

      // Ask the collation which section number the friend name belongs in
      NSInteger sectionNumber = [self.collation sectionForObject:friend collationStringSelector:@selector(name)];

      // Get the array for that section.
      NSMutableArray *sectionFriends = [newSectionsArray objectAtIndex:sectionNumber];

      //  Add the friend to the section.
      [sectionFriends addObject:friend];
    }


    // Now that all the data's in place, each section array needs to be sorted.
    for (index = 0; index < sectionTitlesCount; index++) {

      NSMutableArray *friendsArrayForSection = [newSectionsArray objectAtIndex:index];

      NSArray *sortedFriendsArrayForSection = [self.collation sortedArrayFromArray:friendsArrayForSection collationStringSelector:@selector(name)];

      // Replace the existing array with the sorted array.
      [newSectionsArray replaceObjectAtIndex:index withObject:sortedFriendsArrayForSection];
    }

    self.sectionsArray = newSectionsArray;
}


#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return [self.sectionsArray count];
}


- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return [[self.collation sectionTitles] objectAtIndex:section];
}

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
{
    return [self.collation sectionIndexTitles];
}


- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index
{
    return [self.collation sectionForSectionIndexTitleAtIndex:index];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [[self.sectionsArray objectAtIndex:section] count];
}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    ....
    Person *person = [[self.sectionsArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
    ....
    cell.textLabel.text = person.name;
    ....
    return cell;
}



// Store friend data in a class Person so that we could pass the object to 
// - (NSInteger)sectionForObject:(id)object collationStringSelector:(SEL)selector

// Example Person.h
@interface Person : NSObject

@property (nonatomic, copy) NSString *id;
@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *pictureUrl;

- (id)initWithId:(NSString *)id name:(NSString *)name picture:(NSString *)picUrl;

@end

//查看控制器代码
-（无效）viewDidLoad
{
[超级视图下载]；
[自身条件切除]；
}
-（无效）配置节
{
//UILocalizedIndexedCollation
self.collation=[UILocalizedIndexedCollation currentCollation]；
NSInteger索引，sectionTitlesCount=[[self.collation sectionTitles]计数]；
//有数据的新章节
NSMutableArray*newSectionsArray=[[NSMutableArray alloc]initWithCapacity:sectionTitlesCount]；
//为每个节分配数据数组
对于（索引=0；索引<节标题计数；索引++）{
NSMUTABLEARRY*array=[[NSMUTABLEARRY alloc]init]；
[newSectionsArray添加对象：数组]；
}
//把朋友放在适当的部分
用于（个人*自我中的朋友。朋友）{
//询问排序规则朋友姓名属于哪个节号
NSInteger sectionNumber=[self.collation sectionForObject:friend collationStringSelector:@selector（name）]；
//获取该节的数组。
NSMutableArray*sectionFriends=[newSectionsArray对象索引：sectionNumber]；
//将好友添加到分区。
[sectionFriends添加对象：friend]；
}
//现在所有数据都已就绪，需要对每个节数组进行排序。
对于（索引=0；索引<节标题计数；索引++）{
NSMutableArray*friendsArrayForSection=[NewsSectionsArray对象索引：索引]；
NSArray*sortedFriendsArrayForSection=[self.collation sortedArrayFromArray:friendsArrayForSection collationString选择器：@selector（name）]；
//用已排序的数组替换现有数组。
[newSectionsArray replaceObjectAtIndex:index with object:sortedFriendsArrayForSection]；
}
self.sectionsArray=newSectionsArray；
}
#pragma标记-表视图数据源
-（NSInteger）表格视图中的节数：（UITableView*）表格视图
{
返回[self.sectionsArray count]；
}
-（NSString*）表格视图：（UITableView*）表格视图标题标题标题部分：（NSInteger）部分
{
返回[[self.collation sectionTitles]objectAtIndex:section]；
}
-（NSArray*）sectionIndexTitlesForTableView:（UITableView*）表格视图
{
返回[self.collation sectionIndexTitles]；
}
-（NSInteger）tableView:（UITableView*）分区索引的tableView部分exttitle:（NSString*）标题索引：（NSInteger）索引
{
返回[self.collation sectionforsectionIndexitLeatIndex:index]；
}
-（NSInteger）表视图：（UITableView*）表视图行数节：（NSInteger）节
{
返回[[self.sectionsArray objectAtIndex:section]计数]；
}
-（UITableViewCell*）tableView:（UITableView*）tableView cellForRowAtIndexPath:（NSIndexPath*）indexPath
{
....
Person*Person=[[self.sectionsArray objectAtIndex:indexath.section]objectAtIndex:indexath.row]；
....
cell.textlab.text=person.name；
....
返回单元；
}
//将好友数据存储在类Person中，以便将对象传递给
//-（NSInteger）节对象：（id）对象排序规则字符串选择器：（SEL）选择器
//示例Person.h
@接口人：NSObject
@属性（非原子，副本）NSString*id；
@属性（非原子，副本）NSString*名称；
@属性（非原子，副本）NSString*pictureUrl；
-（id）initWithId:（NSString*）id name:（NSString*）name picture:（NSString*）picUrl；
@结束

Andris的代码非常优秀，但您不需要创建单独的Person类来实现此功能。只需使用NSDictionary代替Person类，如下所示：

首先，创建字典-我将在视图控制器中执行此操作，作为按钮操作的一部分，我将从中调用表视图。您还需要在两个.h文件中声明NSArray*friends和NSNumber*friendsCount属性（用于初始视图控制器和表视图控制器）并合成为_friends _friendscount

- (IBAction)btnAddFriendsTapped:(UIBarButtonItem *)sender {

if (FBSession.activeSession.isOpen){

    __block NSArray *friendsArray = [[NSArray alloc]init];
    __block NSNumber *friendsArrayCount = [[NSNumber alloc]init];

    FBRequest* friendsRequest = [FBRequest requestForMyFriends];
    [friendsRequest startWithCompletionHandler: ^(FBRequestConnection *connection,
                                              NSDictionary* result,
                                              NSError *error) {
                                                friendsArray = [result objectForKey:@"data"];
                                                friendsArrayCount = [NSNumber numberWithInt:friendsArray.count];

                                                NSLog(@"Found: %i friends", [friendsArrayCount intValue]);

                                                for (NSDictionary<FBGraphUser>* friend in friendsArray) {
                                                    NSLog(@"I have a friend named %@ with id %@", friend.name, friend.id);
                                                _friends = [NSArray arrayWithArray:friendsArray];
                                                _friendCount = [NSNumber numberWithInt:[friendsArrayCount intValue]];
                                                }          
        [self performSegueWithIdentifier:@"friendListSegue" sender:self];

     }];
}

} 最后，使用Andris的表代码替换Person类

// Put friends into the appropriate sections
for (NSDictionary<FBGraphUser> *friend in self.friends) {

  // Ask the collation which section number the friend name belongs in
  NSInteger sectionNumber = [self.collation sectionForObject:friend collationStringSelector:@selector(name)];

  // Get the array for that section.
  NSMutableArray *sectionFriends = [newSectionsArray objectAtIndex:sectionNumber];

  //  Add the friend to the section.
  [sectionFriends addObject:friend];
}

//将朋友放入适当的部分
用于（n词汇）
// Put friends into the appropriate sections
for (NSDictionary<FBGraphUser> *friend in self.friends) {

  // Ask the collation which section number the friend name belongs in
  NSInteger sectionNumber = [self.collation sectionForObject:friend collationStringSelector:@selector(name)];

  // Get the array for that section.
  NSMutableArray *sectionFriends = [newSectionsArray objectAtIndex:sectionNumber];

  //  Add the friend to the section.
  [sectionFriends addObject:friend];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
       NSDictionary<FBGraphUser> *person = [[self.sectionsArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
      cell.textLabel.text = person.name;
      return cell;
}